Physical activity has long been recognized as benefiting health. Early exercise guidelines simply recommended a minimum amount of physical activity within a certain time period—typically a certain number of minutes of exercise within a day or week. More recent research suggests that some patterns of physical activity benefit health more than others. In particular, the frequency and intensity of physical activity influence the degree of health benefit. Long periods of inactivity have been linked to poorer health even among individuals who get recommended amounts of exercise. In addition, more intense physical activity is associated with health benefits not found at lower intensities.
It is impractical, if not impossible, for individuals to constantly monitor the frequency, intensity, and total amount of their physical activity without the aid of technology. Over the last few years, small, inexpensive accelerometers have come to be used in an increasing number of devices including activity trackers which measure activity levels of the user. Activity trackers typically include a computer processor and other components to analyze the accelerometer's data output.
Many organizations including employers and insurance companies encourage their members to exercise more. Many of these organizations operate programs to monitor the physical activity of their members and determine whether they are meeting physical activity goals. Members often receive rewards of various kinds if they meet activity goals.